FuncX Container Service

The Container service runs in a container using FastAPI. It's responsible for creating and managing container environments for running functions on funcX.

Configuring the service

A configuration file (titled '.env') is required at the top level of the repository which houses the configuration settings necessary to run the serivce. This file uses the VAR=VAL syntax and currently requires the following VARs defined:

WEBSERVICE_URL=<url for the webserivce that issues requests to the container service>
REGISTRY_USERNAME=<registry username>
REGISTRY_PWD=<registry password>
REGISTRY_URL=<url to registry>
BUILD_TIMEOUT=<repo2docker max time (seconds)>

WEBSERVICE_URL is the webservice for the funcx service that registers the user submission for a container build via the sdk

The REGISTRY variables define the access information for the registry to which the resulting image built by the container service should be stored

The BUILD_TIMEOUT is an integer value representing the amount of time (in seconds) that the repo2docker process has to successfully complete before it is terminated. Note that this does not include the time required to push the image up to the specified repository (which could take a few minutes). Defaults to 30 minutes if no value is specified in the '.env' file.

Running the service

Development Setups

For the full container service experience you will want a local instance of the funcX webservice running, along with a compatible version of the funcX SDK.

Install the container_service branch of the sdk:

In a clean virtual environment install the container service development branch of the funcX SDK

pip install git+https://github.com/funcx-faas/funcX.git@container_service#subdirectory=funcx_sdk

Run the Container Service

There are two options for running the container service. If you just need it to be available, you can run a published docker image:

docker run --rm -it --env WEBSERVICE_URL=http://host.docker.internal:5000 -p 8000:8000 funcx/container-service:dev

This uses a macOS Docker feature for accessing the host's ports from within a docker container.

For development and debugging purposes, you can run the Container Service in pyCharm or other IDE. For this, setup a runtime configuration that runs the script main.py. You will need to provide an environment variable to the process that sets WEBSERVICE_URL=http://localhost:5000

Run the FuncX Web Service

Likewise, there are the same two options for running the web service. If you just want to run the webservice you can use the container_service tagged image. In this case, you need to provide the service with a config file. A working config file is checked into this repo, web_svc_app.conf. This gets mounted into the container and run as:

docker run --rm -it -p 5000:5000 \
       --mount "type=bind,source=$(pwd)/web_svc_app.conf,target=/opt/app.conf" \
       --env APP_CONFIG_FILE=/opt/app.conf \
       funcx/web-service:container_service

For development and debugging you can run the web service in pyCharm. That IDE directly supports flask apps. Just add an environment variable,

APP_CONFIG_FILE=../funcx-container-service/web_svc_app.conf

The web app will be running on port 5000 and expecting the container service on port 8000.

Taking the Container Service out for a Spin

With the container service enabled SDK, it's easy to submit a container build request:

from funcx import ContainerSpec, FuncXClient

fxc = FuncXClient(funcx_service_address="http://localhost:5000/v2")
container_uuid = fxc.build_container(
    ContainerSpec(
        name="MyContainer",
        apt=[
            "dvipng",
            "ghostscript"
        ],
        pip=[
            "cycler==0.10.0"
        ],
    )
)

print(f"Building {container_uuid}")
print(f"status is {fxc.get_container_build_status(container_uuid)}")

You can run the service inside a docker container.

$ docker build -t container_service:latest .
$ docker run -d -p 5000:5000 container_service:latest

Or set up a build environment with

$ pip install -r requirements.txt

Then start the server with

$ uvicorn funcx_container_service:app --reload

The full API is documented at http://server:port/docs. This includes definitions of callback routes, which are examplars of externally hosted routes that the container service will rely on for complete functionality.

The Docker daemon needs to be running (with the control socket) bind mounted into the container if applicable. Also requires Singularity 3.x in the build environment.

Testing

Two types of tests so far; use pytest -m "not integration_test" tests/resources to only run unit tests.

To run integration tests, start docker as above and use
`pytest -m "integration_test" tests/resources`